Coffin Joint Osteoarthritis

This horse was presented to our clinic for a lameness investigation. His owner complained that the horse hadn’t felt right for the last few weeks.

On examination it was found there was bilateral effusion (swelling) of both front coffin joints. Effusion is usually but not always present in horses with coffin joint arthritis. If there is swelling in the coffin joint it is felt just above the coronary band.The horse was bilaterally lame in front and he was positive to distal limb flexion tests (these tests stress the coffin, pastern, and fetlock joints).

We performed intrasynovial analgesia (joint blocks) of both front coffin joints which improved the lameness but a bilateral abaxial nerve block (desensitizing the foot and pastern) was required to eliminate the lameness. The source of the lameness was therefore located to the limb below the fetlock joint.

Radiographs of both front feet and pastern regions showed osteoarthritis of both front coffin and pastern joints. It was also discovered that the horse had a poor foot balance. A combination of joint medication and corrective shoeing (elevating the heels) will be used to treat the patient.

Coffin joint osteoarthritis is a common cause of lameness/poor performance in all equestrian disciplines. Osteoarthritis of the coffin joint can be primary or secondary. Primary OA can be due to repetitive trauma. Horses with a broken pastern axis (forward or backwards) and other hoof imbalances appear particularly prone to repetitive trauma of the coffin joint.

Catching the condition early and ensuring correct foot imbalances improves the horses prognosis.